How big is too big ~ Carbs

I had a quick browse back thru the posts .. and I am sure this has been hashed before..

But I am considering endeavouring to adapt two carbs off a R1 Yammy but the venturis are 40mm !

I know RGM Cumbria UK are offering an adaptor and rubber mounts.. but its a big jump from 32 -40 mm ~ plus I then have to consider the ports..

What are the realities of a creating an even greater 'venturi effect" by fitting such a carb ~

(I for one have had a gut full of tinkering with dodgy Amal and SS inserts and blah blah!)

SS

My 600 CBR has really big (I think 38mm) carbs on each cylinder and they are excellent, however the CBR will turn 13,000 rpm and the carbs are CV's.
I think dual 40mm's will be an unhappy experience for the Norton, I doubt that you can get the airflow to get them to work properly. Dual 34's or maybe even 36's might work, but unless your full on racing why bother?

Scooter